It has been known to utilize capaciflector/capacitive sensing for robotic collision avoidance and for “virtual feel” robotic assembly and servicing as long as the objects operated on were electrical conductors. Further, capacitive technology has been used for quality control measurement in industry and government, including dielectric glass quality control. Capacitive sensing technology has also been used for precision alignment of components and sub-systems in scientific instruments.
However, sensing insulating materials has been found to be more problematic than sensing electrical conductors. For example, known sensors may be unable to distinguish between an electrical conductor at a distance far away and an insulator at a close range. Also, the known capacitive technology is not able to accurately sense a dielectric film that is over a conductor.
Basic capacitive technologies measuring dielectric materials, such as glass, have several limitations. To gain sufficient electric field strength to pass through the stand-off range to the glass, to penetrate the glass and to return to electrical ground, a transformer may typically be used to amplify the electrode voltage by approximately a factor of 100. Even so, this type of system does not work near the edges of the glass. For example, these systems fail to discriminate between edge losses, alignment errors, and glass anomalies.
Capacitive sensing systems used for precision alignment of components and subsystems in scientific instruments have been successful, but are more than an order of magnitude less precise than embodiments of the present invention that employ a driven ground circuit with capacitive sensing or capaciflector technology.
Inverting amplifiers are not normally used to terminate a load and, usually provide no direct information about the electric current passing through the load. Inverted amplifiers may be used to terminate a load with the virtual ground feature performing that function. However, in this role, the input resistance may be unnecessary and reduces its sensitivity as a ground termination.
Thus, a problem exists in the art in connection with an inability of known sensors to accurately detect insulators. The insulators may be detected in general, however, there continues to be a problem of more precisely identifying and characterizing insulators and their relative permittivity.
Accordingly, it may be desirable to provide an electrical circuit for a sensor system that can accurately detect an insulative material, such as a dielectric. It may also be desirable to provide an electrical circuit for a sensor system which accurately detects and quantifies an insulative material. Further, it would be desirable to provide a sensor system that accurately detects an insulative material utilizing a driven ground electrical circuit that may be applicable to various sensing environments and sensing systems.